package com.yyxx.wechatfp.util;

import java.io.UnsupportedEncodingException;

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;

///* AES对称加密解密类 */ 
public class AESUtil {

private static final String CipherMode = "AES/ECB/PKCS5Padding";

// /** 创建密钥 **/
private static SecretKeySpec createKey(String password) {
    byte[] data = null;
    if (password == null) {
        password = "";
    }
    StringBuffer sb = new StringBuffer(32);
    sb.append(password);
    while (sb.length() < 32) {
        sb.append("0");
    }
    if (sb.length() > 32) {
        sb.setLength(32);
    }

    try {
        data = sb.toString().getBytes("UTF-8");
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    }
    return new SecretKeySpec(data, "AES");
}

// /** 加密字节数据 **/
public static byte[] encrypt(byte[] content, String password) {
    try {
        SecretKeySpec key = createKey(password);
        System.out.println(key);
        Cipher cipher = Cipher.getInstance(CipherMode);
        cipher.init(Cipher.ENCRYPT_MODE, key);
        byte[] result = cipher.doFinal(content);
        return result;
    } catch (Exception e) {
        e.printStackTrace();
    }
    return null;
}

// /** 加密(结果为16进制字符串) **/
public static String encrypt(String content, String password) {
    byte[] data = null;
    try {
        data = content.getBytes("UTF-8");
    } catch (Exception e) {
        e.printStackTrace();
    }
    data = encrypt(data, password);
    String result = byte2hex(data);
    return result;
}

// /** 解密字节数组 **/
public static byte[] decrypt(byte[] content, String password) {
    try {
        SecretKeySpec key = createKey(password);
        Cipher cipher = Cipher.getInstance(CipherMode);
        cipher.init(Cipher.DECRYPT_MODE, key);
        byte[] result = cipher.doFinal(content);
        return result;
    } catch (Exception e) {
        e.printStackTrace();
    }
    return null;
}

// /** 解密16进制的字符串为字符串 **/
public static String decrypt(String content, String password) {
    byte[] data = null;
    try {
        data = hex2byte(content);
    } catch (Exception e) {
        e.printStackTrace();
    }
    data = decrypt(data, password);
    if (data == null)
        return null;
    String result = null;
    try {
        result = new String(data, "UTF-8");
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    }
    return result;
}

// /** 字节数组转成16进制字符串 **/
public static String byte2hex(byte[] b) { // 一个字节的数，
    StringBuffer sb = new StringBuffer(b.length * 2);
    String tmp = "";
    for (int n = 0; n < b.length; n++) {
        // 整数转成十六进制表示
        tmp = (java.lang.Integer.toHexString(b[n] & 0XFF));
        if (tmp.length() == 1) {
            sb.append("0");
        }
        sb.append(tmp);
    }
    return sb.toString().toUpperCase(); // 转成大写
}

// /** 将hex字符串转换成字节数组 **/
private static byte[] hex2byte(String inputString) {
    if (inputString == null || inputString.length() < 2) {
        return new byte[0];
    }
    inputString = inputString.toLowerCase();
    int l = inputString.length() / 2;
    byte[] result = new byte[l];
    for (int i = 0; i < l; ++i) {
        String tmp = inputString.substring(2 * i, 2 * i + 2);
        result[i] = (byte) (Integer.parseInt(tmp, 16) & 0xFF);
    }
    return result;
}
}